Metal doors may be fabricated from two or more skins parts. Each of the skins' edges are usually folded to form a profile which would complementarily engage one another to form an interlocking seam.
One example of such metal door construction is shown in FIG. 1 which comprised of a bottom skin (10) and a top skin (20). Conventionally, the edge portions of a completely installed door as shown in the FIG. 1 may be referred to as the stile or longitudinal edge (12, 22) (the latter term is used in this specification) and the rail (14, 24) or the vertical edge (the former term is used in this specification).
The longitudinal edges (12, 22) of the skins are folded in a profile that will complementarily hem or lock each other when engaged. One such example is shown in FIG. 1 wherein the bottom skin's opposing longitudinally edges (12) are each bent upwardly (15) to form the full thickness of the door edge and the ends of the bent portion is folded outwardly to form an downward flange (17) which is flush with the outer door edge.
The top skin's longitudinal edges may be bent downwardly (23) to form less than the full thickness of the door edge. FIG. 1 shows an example of the thickness of the top skin's longitudinal edge to be about half the full thickness of the door edge. The ends of the bent portion is then folded inwardly to form an upward flange (25) which, upon engaging the corresponding downward flange (17) of the bottom skin edge, complementarily interlock with the bottom skin's folded ends to form the door edge seam.
To assemble the two pieces of skins together by slotting in the flanges (17, 25) of the skins into a mutually hemming or interlocking arrangement, one may manually align the edge profiles of the skins end-to-end and push to slot in the flanges. Manual assembly is usually tedious and laborious.
It is therefore the object of the present invention to provide a method of assembling a two-piece skin door in a mechanised or automated manner. It is a further object of the present invention to provide an apparatus for carrying out the method of assembly in an automated or mechanical manner.